Some objects have individualized markings that distinguish them from other similar objects. For example, a secure token that generates one-time passwords (OTPs) has a serial number etched into its surface by which it may be uniquely identified.
One approach to providing an individualized marking to an object involves laser etching the marking in the object. In such an approach, a laser such as a carbon dioxide laser with sufficient power to burn a hole in the object's surface irradiates a template of the marking on a portion of the object. An operator may control the direction of the laser radiation so that the laser burns the marking in an expected place on the object. For example, when the laser is etching a serial number on a token, the operator may aim the laser so that the number is etched below a display of the OTP.
When many similar objects each require individual markings via laser etching, the orientation of the laser involved may require calibration. Conventional approaches to calibrating the orientation and position of an etching laser involve manual measurement of a deviation from the desired location of a test mark on a calibration object. For example, the laser etches the marking on the calibration object at a current position. An operator then observes the difference in position between the current position and the intended position. The operator then uses the difference to adjust the orientation of the laser. The difference may be determined by an estimation of the misalignment distance.